The accumulation of dirt and/or precipitation on the exterior of side windows of a motor vehicle is a common problem for operators of motor vehicles. This accumulation prevents and obstructs the operator's visibility to the periphery and more importantly, the ability to see in the exterior rear view mirror any traffic approaching in the adjoining lane.
The problem of impaired sight through a side window has been addressed by various patents. For example, the Mills U.S. Pat. No. 3,859,899 discloses a side mirror unit which draws air from the interior of the vehicle through a grille and out to the periphery of the mirror and to a vent directed to the exterior of the side window. It utilizes a "slip stream" of ambient air passing over the side mirror unit to draw the air out of the interior of the car, but this aspirating affect only provides a minimal air flow rate across the window which can not clear the window of dirt, debris and frozen precipitation. Gebhard U.S. Pat. No. 4,462,303 disclosed a sail mirror assembly which is connected to the vehicle's interior ventilation system and provides a door to the interior of the vehicle. This invention utilizes the reduced air pressure around the periphery of the mirror to draw the interior air of the vehicle through the door into the mirror housing, around the mirror assembly to the periphery of the mirror. This invention did not address the problems of dirt, debris and precipitation accumulating on the exterior of the side window and instead provided ventilated air over the interior of the side window. Also, the Gebhard invention is connected to the ventilation system which is more costly and generally ineffective because of the restrictions to the air flow by the bends of the ductwork leading to the mirror and side window.
Among the objectives of the invention are to provide (1) an exterior mirror assembly that clears and cleans debris and precipitation from a side window from which an operator may view out; (2) includes a passage which mixes conditioned interior air with ambient air to be directed to the exterior of a side window; (3) includes a conditioned interior air flow regulator; and (4) which is of simple and economical design, manufacture and assembly.
In accordance with the invention, an exterior rear view mirror assembly has a mirror element enclosed by a housing which is coupled to a mounting structure attached to the side of a vehicle. Interposed between the mirror housing and the mounting structure is a passage with an inlet facing towards the forward section of the vehicle and an outlet facing towards the exterior of a side window of the vehicle. The mounting structure has a duct which communicates with the interior of the vehicle and the passage. As the vehicle moves forward the ambient air flows through the passage and draws conditioned interior air through the mounting structure into the duct and mixes both air flows in the passage before exiting through the outlet against the exterior of the side window. The flow of interior air is controlled by the operator by adjusting a flow regulating system. An important advantage of this present invention is that the conditioned air flow across the exterior of the side window is of sufficient force and temperature to keep debris, dirt and precipitation from accumulating on the exterior of the window.
Other objects and features of the invention will be apparent from the following description and claims in which the invention is described together with details to enable persons skilled in the art to practice the invention, all in connection with the best mode presently contemplated for the invention.